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Biomedical subjects

B Mayer

Publications and source records attributed to B Mayer.

At least 343 records · Page 19Linked to original sources
PubMed1989

Ca2+-dependent formation of an L-arginine-derived activator of soluble guanylyl cyclase in bovine lung.

In a fraction of cytosolic proteins from bovine lung, soluble guanylyl cyclase was concentration-dependently stimulated by L-arginine but not by D-arginine. Stimulation was up to 20-fold with an EC50 of about 3 x 10(-5) M. Activation of guanylyl cyclase by L-arginine was dependent on NADPH (EC50 about 5 x 10(-7) M) and Ca2+ (EC50 about 1.4 x 10(-6) M). The activation by L-arginine was inhibited by NG-monomethyl-L-arginine and hemoglobin. The effect of L-arginine was dependent on the protein concentration and was not observed in preparations of purified gyanylyl cyclase. These results suggest that bovine lung contains a Ca2+-regulated enzyme or enzyme system which converts L-arginine into an activator of soluble guanylyl cyclase.

Animals↗
PubMed1989

[Tissue expanders in plastic surgery of the head and neck. Indications and use].

Tissue expansion allows a functional as well as an aesthetic reconstruction of local defects and thus corresponds to the actual state of the art in plastic surgery.-Tissue expansion provides tissue of the same quality for the repair of defects without leaving deformities on the donor site. It creates local flaps with skin of the same texture, colour and preserved sensitivity.-The use of tissue expanders has grown enormously during the last few years.-A higher rate of complications on the cheek and on the neck must be taken into account.

Head and Neck Neoplasms↗
PubMed1989

[Reconstruction of the upper lip using the mucosal eversion technic].

A one-stage reconstruction technique for upper lip defects is presented. This technique uses everted mucosal advancement flaps for the reconstruction of the vermilion border of the lip. It is an extension of Meyer's method employed in the reconstruction of the lower lip (1973) and differs from Camille Bernard's procedure in that horizontal incisions with bilateral triangular skin excisions are used instead of the more unaesthetic perpendicular incisions in the nasolabial fold, leaving a scar along the vermilion border. The method is suitable for reconstructing the upper lip after excision of up to 80% of its substance, and is superior to traditional methods in terms of both the functional and aesthetic results obtained.

Adult↗
PubMed1988

[Surgical treatment of severe lower lid ectropion with a transplant of skin and perichondrium].

A surgical procedure is described for severe ectropions of the lower lid which cannot be treated successfully by conservative measures or minor surgery. This technique, employing a perichondrocutaneous graft, is superior to traditional methods in terms of both the functional and esthetic results. The composite graft is obtained from the anterior surface of the auricular choncha. In about 50% of the patients the postoperative biopsy showed a chondrogenic activity of the transplanted perichondrium substituting the tarsus. In the other cases, though no cartilaginous growth was noted, there was an intense proliferation of collagen fibers stabilizing the lid and the tarsal region. This procedure leads to both functional and natural esthetic rehabilitation and satisfies the criteria which techniques in plastic surgery have to meet today.

Adult↗
PubMed1988

[Abdominoplasty--personal surgical guidelines].

An account is given by the authors of their own guidelines for surgical treatment of deformities of the anterior abdominal wall. The procedures described are based on experience obtained from 866 surgical interventions at the first author's clinic, between 1959 and 1987. Indications, techniques, and complications are discussed in some detail.

Abdominal Muscles↗
PubMed1988

[Reconstruction of the lower third of the face--microsurgical monobloc transfer with vascularized bone].

The authors present two microsurgical options of the reconstruction of the lower third of the face. They outline a systematisation of indications and techniques and emphasise versatility and flexibility of free flaps compared to pedicled flaps, and describe the advantages of the vascularisation and the techniques of the iliac crest osteocutaneous flap and the parascapular cutaneous-latissimus dorsi osteomyocutaneous flap which was developed by Nassif.

Bone Transplantation↗
PubMed1988

[Facial burns--treatment of sequelae].

The treatment of the sequelae of facial burns is still a controversial subject. The authors present a retrospective study of 1516 cases between 1967 and 1987. They suggest a more conservative approach of the therapy in purely aesthetic lesions. Therefore, they wait for the "softening" of the scars and start an operative treatment after the maturation of the collagen connective tissue. Functional sequelae have to be treated earlier according to their dimension and according to the aesthetic units affected.

Burns↗
PubMed1988

[Reflections on the use of fluid dimethylpolysiloxan in plastic surgery of the head and neck].

The authors present retrospectively results and complications of 47 treatments with fluid dimethylpolysiloxane (silicone). The injections were not administered in the author's surgical department. The history of fluid silicone, its tissue reactions and the aesthetic results obtained are described. Different types of complications and their management are discussed. According to the authors' experience fluid dimethylpolysiloxane has not proved to be a proper material for plastic reconstructive and aesthetic treatment in the head and neck region.

Dimethylpolysiloxanes↗
PubMed1987

Quantitative measurement of 5-, 12-, and 15-hydroxyeicosatetraenoic acid together with 12-hydroxyheptadecatrienoic acid by stable isotope dilution gas chromatography-negative ion chemical ionization-mass spectrometry.

A stable isotope dilution gas chromatography-negative ion chemical ionization-mass spectrometry assay for simultaneous quantitative measurement of 5-hydroxyeicosatetraenoic acid (HETE), 12-HETE, 15-HETE, and 12-hydroxyheptadecatrienoic acid in one single GC/MS run was established. 18O2-Labeled analogs as internal standards, prepared according to conventional procedures, were found to be useful for this application. A sample processing and derivatization sequence providing highly purified compounds with a recovery of 42.7% was elaborated. The detection limit was in the femtomole range.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1987

Formation of 6,15-diketoprostaglandin F1 alpha from prostaglandin G2 by bovine aortic endothelial cells.

Besides 6-ketoprostaglandin F1 alpha, bovine aortic endothelial cells also produced considerable amounts of 6,15-diketoprostaglandin F1 alpha from arachidonic acid, either exogenously added or released from cellular phospholipids. Incubations of particulate fractions of endothelial cells with the cyclic endoperoxides prostaglandin G2 and prostaglandin H2 showed that 6,15-diketoprostaglandin F1 alpha is formed by the action of prostaglandin I2 synthetase on prostaglandin G2. The labile metabolite 15-hydroperoxyprostaglandin I2 is then converted nonenzymatically to the 15-keto derivative. In the presence of reduced glutathione, quantitative analysis of both metabolites by gas chromatography-mass spectrometry showed a significant decrease of 6,15-diketoprostaglandin F1 alpha formation, whereas prostaglandin I2 synthesis was markedly increased. This shift seems to be due to a stimulation of peroxidase by GSH, a well known cofactor of this enzyme. Thus, it seems that a decreased endothelial prostaglandin I2 formation may occur when cellular glutathione levels are reduced as a consequence of oxidant injury and lipid peroxidation. Additionally, ferrous ions seems to be involved in the regulation of endothelial prostaglandin I2 synthesis, since Desferal, a specific ferrous ion chelator that might have antimetastatic properties, produced a pronounced shift from 6,15-diketoprostaglandin F1 alpha to the 6-keto derivative, i.e., prostaglandin I2.

6-Ketoprostaglandin F1 alpha↗
PubMed1987

Measurement of prostaglandins, thromboxanes and hydroxy fatty acids by stable isotope dilution gas chromatography/mass spectrometry.

A method for measurement of PGF2 alpha, PGE1, PGE2, 6-keto-PGF1 alpha, TXB2, 2,3-dinor-TXB2 as well as 5-, 8-, 9-, 11-, 12-, 15-HETE and HHT, utilizing negative ion chemical ionization GC/MS is presented. A highly efficient separation and purification procedure prior to the derivatization sequence allows quantification of the arachidonic acid metabolites described in two GC/MS runs. The detection limit was in the femtomole range. Application of the method to the quantitative profiling of arachidonic acid metabolites in various tissues and incubation media is demonstrated.

Gas Chromatography-Mass Spectrometry↗
PubMed1987

[Rhytidoplasty: perioperative guidelines. Particular technical basic details].

The authors present their philosophy of rhytidoplasty and the basic technical details of this kind of operation. The aging face often causes psychological as well as social problems that make patients go to a facial plastic surgeon. The authors stress the importance of an intensive preoperative information. Basic details of preoperative preparation, surgical technique and postoperative care are emphasised because they represent decisive steps in terms of the aesthetic results obtained. These details proved to be mostly important in the course of about 5000 rhytidoplasties.

Face↗